The poll suggests the debate over a Supreme Court nomination could help Biden motivate his supporters: A 64 percent majority of Biden supporters say the vacancy makes it “more important” that Biden win the election, compared with 37 percent of Trump supporters who say the same about Trump winning reelection. Biden supporters are 19 percentage points more likely to say the vacancy makes it “much more important” that their candidate win, at 48 percent, compared with 29 percent of Trump supporters.

Those results suggest a reversal in the recent postures of both parties. In 2016, national exit polling found Trump voters were more likely to say Supreme Court appointments were “the most important factor” in their vote, at 26 percent, compared with 18 percent among Hillary Clinton voters.